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Assessment of Ecological Carrying Capacity of Royal Bengal Tiger in Chitwan- Parsa Complex, Nepal

Summary

Nepal has been carrying out successful tiger conservation since 1970s. Over the years, once dwindling,
tiger population in lowlands have recovered. Nationwide tiger surveys have shown and steady increase
in tiger population in the country. Nepal is on course to be one of the first tiger range countries to
fulfil its commitment and achieve the target of doubling tiger numbers by 2022 set during the Global
Tiger Summit in 2010. However, significant challenges remain ahead, particularly ensuring sufficient
secured interconnected habitats for the species to be conserved over the long term, along with minimal
human-tiger conflict. This study was conducted, on a special request by the Government of Nepal,
to establish a method for estimating tiger ecological carrying capacity (ECC) of a site and provide a
baseline ECC estimate of tigers in the Chitwan-Parsa Complex, a priority tiger conservation landscape.
The approach and estimate would then help Government of Nepal to develop appropriate management
interventions to conserve optimum number of tigers over the long term.

Densities of tigers, the largest felid, are mediated mainly by available biomass (or abundance) of
medium-to-large ungulates. As part of this study, a systematic line-transect distance sampling survey
provided density estimates for all ungulate species in the plains and Chure hills of the Chitwan-Parsa
Complex. This was the first complete ungulate survey of both habitats in the Complex. Tiger ECC
models based on prey biomass and prey densities provided similar estimates. Currently, Chitwan-
Parsa Complex can support a significant population of approximately 175 tigers with Chitwan able to
support 136 tigers and Parsa 39 tigers. Currently, Chitwan NP has an estimated 93 tigers and Parsa NP
18 tigers.

The study, however, emphasis the development of a specific tiger ECC model for the Terai-Arc
Landscape incorporating improved ecological data particularly on average tiger meat intake and kill
rate. The study also recommends the development of a dedicated tiger conservation management
plan for the Chitwan-Parsa Complex, through a Population and Habitat Viability Assessment (PHVA)
workshop, to guide protected area managers and policy makers in conserving optimum number of
tigers within the Complex in the long term.